I. Field of the Invention
The present invention relates generally to tools for repairing vehicle tires, and more particularly to a tool for installing a valve stem in a wheel rim adapted to hold a tubeless tire.
II. Description of the Prior Art
Vehicle rims are often constructed to retain tubeless inflatable tires wherein the edges of the tire seal against the side wall of the rim and the hollow tire is inflated with air. Typically, a valve stem having a one way valve extends through a stem hole in the wheel rim so that one end of the stem is in fluid communication with the hollow chamber enclosed by the tire. The valve in the stem permits air to be introduced through the stem and into the tire chamber, but prevents air from escaping from the chamber through the valve stem. Quite often, the valve stem is provided with an end cap which treadably engages the exposed end of the stem to protect the valve mechanism therein.
The other end of the valve stem usually includes a pair of spaced apart, resilient ribs extending radially outwardly from the body of the stem. The resilient ribs sealingly engage the periphery of the stem hole on opposite sides of the wheel rim wall. The resilient ribs anchor the stem within the wheel rim and prevent leakage of air from the tire chamber around the valve stem. Of course, the resilient ribs are deformable so that the stem can be positioned within the stem hole.
Previously known tools are not well adapted for inserting the valve stem in a stem hole of the wheel rim. For example, use of a screwdriver blade to wedge portions of the ribs into the stem hole, a common way to mount valve stems, can often cut or otherwise damage the ribs and thus cause leakage of the seal around the stem hole. Moreover, insertion of the valve stem with such a tool can be difficult and time consuming in view of the resilience of the ribs and the fact that they tend to expand to a shape substantially larger than the stem hole.
Tools are also known such as disclosed in U.S. Pat. No. 3,387,354 which have a pusher rod advanced by action of a trigger handle on notches placed on the rod. The pusher rod advances a valve stem through a tapered spout to force the valve stem into the stem hole. However, tools of this type are relatively complex and expensive to manufacture and have a number of moving parts biased by springs which wear out after repeated use.